Compatibility of Low‐Dimensional Perovskites in n–i–p and p–i–n Perovskite Solar Cells

ABSTRACT Low‐dimensional (LD) perovskites have emerged as a cornerstone strategy for mitigating the intrinsic instability and suppressing interfacial non‐radiative recombination in 3D perovskites. Nevertheless, the intrinsic charge transport anisotropy of LD phases fundamentally constrains their compatibility with device architectures, raising a key question regarding their integration into n–i–p and p–i–n configurations. This review systematically elucidates the spatial continuity and crystallization kinetics of LD perovskite heterojunctions, establishing a comprehensive mechanistic framework for architectural compatibility. Analyses indicate that 0D and 1D systems, lacking continuous charge‐transport pathways, primarily function as localized passivation agents. The architecture compatibility of quasi‐2D/3D perovskite systems is governed by their vertical phase distribution rather than an intrinsic preference, with buried low‐n/high‐n gradients generally benefiting p–i–n devices and surface‐oriented LD phases commonly employed in n–i–p architectures. For pure 2D/3D systems, architectural compatibility is achieved through tailored interfacial positioning, acting as top‐layer barriers for surface recombination suppression in n–i–p devices and bottom‐layer templates for crystallization regulation and strain relief in p–i–n structures. By elucidating the interplay between the spatial distribution of LD perovskites and device architectures, this review provides mechanistic guidelines for structure–architecture co‐design in perovskite solar cells.